Benzo-1, 2-dithiolium compounds



United States Patent O 3,141,891 BENZO-LZ-DITHIOLIUM COMPOUNDS Erwin Klingsberg, Mountainside, N.J., assignor to American Cyanamid Company, Stamford, Conn., a corporation of Maine No Drawing. Filed June 20, 1962, Ser. No. 203,724 3 Claims. (Cl. 260-327) wherein each of the R and R radicals is either hydrogen, chloro, bromo, fluoro, nitro, lower alkyl, or lower alkoxy; or together they represent a benzo ring; and each of the R and R radicals is lower alkyl, lower hydroxyalkyl, aryl, aralkyl, or lower cyanoalkyl. Aryl groups that are present may be monocyclic or bicyclic and may contain up to three lower alkyl, halo (e.g., chloro), nitro, or lower alkoxy groups. The anion X- may be derived from any acid, but acids that are not too weak (pKa not above 4) are preferable since they give stable salts.

These dyestuffs can be prepared by condensing a 4,5- benzo-l,2-dithiole-3-thione with a tertiary aniline in the presence of trichloromethanesulfenyl chloride ..or,thiophosgene:

It is an advantage of this condensation reaction that it proceeds readily at room temperatures, but higher and lower temperatures, preferably in the range of l C. to 35 C. may be employed. g

If it is desired, an inert diluent, preferably an organic liquid which is a solvent for the trithione starting material, may be employed. This may be chosen from conventional solvents such as an aromatic hydrocarbon (e.g., toluene), a lower alkanol (e.g., ethanol), or chloroform. The thiophosgene or trichloromethanesulfenyl chloride may be mixed with the dithiolethione prior. to addition of the tertiary aniline, instead of forming a mixture of all three components at once.

After reaction is complete, the product is converted to the desired salt by treatment with an inorganic or organic acid, e.g., perchloric, hydriodicyhydrobromic, fluoboric, or picric acid.

Tertiary anilines which may be employed include:

(1) Lower N,N-dialkylanilines such 'as N,N-dimethyl aniline, N,N-di-ethylaniline, N,N-di-butylaniline, N-

ethyl-N-methylaniline and N-cyclohexyl N methyl aniline;

(2) N-lower alkyl-N-arylanilines such as N-methyldiphenylamine, N-ethyl-N-a-naphthylaniline, N-methyl- N p tolylaniline, N-propyl-p-methoxydiphenylarnine, and N-butyl-p-chlorodiphenylarnine;

(3 N-fl-cyanoethyl-N-methylaniline;

(4) N- 6-hydroxyethyl-N-methylaniline; and

(5) N-methyl-N-benzylaniline.

Among the 4,5-benzodithiolethiones which may be employed are the following:

(l 6-chlorobenz0-1,2-dithiole-3-thione,

(2) 6,7-dimethylbenzo- 1 ,2-dithiole-3 -thione, (3) 6-nitrobenzo-1,2-dithiole-3-thione,

(4) 5,6-dimethoxybenzo-1,2-dithiole-3-thione, (5 6-fluorobenzo-l,2-dithiole-3-thione,

(6) Naphtho [2,3-c] 1,2-dithiole-3-thione, and (7) Naphtho[1,2c] 1,2-dithiole-3-thione.

As a class, benzodithiolethiones are known to be available by a variety of reactions, including the action of P 8 on an o-mercapto aromatic carboxylic .acid (e.g., thiosalicyclic acid) or the corresponding disulfide (e.g., 2,2'-dithiodibenzoic acid). When desired or convenient, any benzodithiolethione not readily available from another source, may be obtained by the use of one of the foregoing preparatory methods.

Compounds of the present invention may be used in the customary manner as dyestuffs for textiles. Thus, they impart intense shades to acrylic fibers.

The following examples, in which parts are by weight, unless otherwise noted, and degree are in centigrade, are presented to further illustrate the present invention.

Example 1 CH l R CHa Three parts by volume of trichloromethanesulfenyl chloride are added to a solution of 5.0 parts of 4,5-benzo- 1,2-dithiole-3-thione in 50 parts (by volume) of toluene.

After completion of the reaction, the product is filtered, washed with benzene, and added to a solution of 3.0 parts by volume of dimethylaniline in 50 parts by volume of ethanol. 011 addition of perchloric acid, the deep blue product separates as the perchlorate salt, which is recrystallized from methanol. It gives bright blue dyeings on polyacrylonitrile fibers.

When N methyl N butylaniline, N-cyclohexyl-N- methylaniline and N,N-dibutylaniline are substituted'in the foregoing procedure, the corresponding 4,5-benzo-3- tertiary aminophenyl-1,2-dithiolium derivatives are obtained.

Example 2 c 3 4 lized from methanol. It dyes polyacrylonitrile bright This product is prepared by the procedure of Example blue shades. 1, using N-methyldiphenylarnine instead of dimethyl- Example 3 aniline. It gives blue dyeings on polyacrylonitrile. I claim:

5 1. A compound of the formula:

S--S R2 This roduct is made by the procedure of Example 1, replacing the dimethylaniline by an equivalent amount 7 I 3 of N-methyl-N-cyanoethylaniline. It gives a redder blue a dyeing on polyacrylonitrile than is obtained with the prodnet of Example 2' Example 4 wherein R and R are selected from the group consisting of hydrogen, chloro, bromo, fluoro, nitro, lower alkyl,

lower alkoxy, and together benzo; R and R are individ- I ually selected from the group consisting of lower alkyl, fl-hydroxyethyl, phenyl, naphthyl, phenyl lower alkyl and ,B-cyanoethyl; said phenyl, naphthyl and benzo moieties containing up to three substituents selected from the group consisting of lower alkyl, halo, nitro and lower alkoxy; @AWCHM 010 r and X is an anion of an acid of pKa not above 4. i 2. A compound of claim 1 wherein the anion is selected from the group consisting of perchlorate, iodide,

bromide fluoborate and picrate. ThIS product is made by the procedure of Example 1, a replacing the benzo-1,2-dithiole-3-thione by an equivalent A process of prepanng the compound of the formulaof naphtho[2,3-C]-l,2-dithiole-3-thione. The product gives blue dyeings on polyacrylonitrile.

R Example 5 5\\ Ii L I W-Qat-om 0104- 3 wherein R and R are selected from the group consisting This product is made by the procedure of Example 1, 40 of hydrogen, ChlOIO, m filloro, Intro, lower alkyl, using an equivalent amount of 6-chloro-benzo-1,2-dithiolelower alkoxy, together nz R and R are llldlVld- 3-thione. It gives bright blue dyeings on polyacrylonitrile ually Selected from the group COHSlStlllg f lower alkyl, fib ,8-hydroxyethyl, phenyl, naphthyl, phenyl lower alkyl and Example 6 B-cyanoethyl; said phenyl, naphthyl and benzo moieties containing up to three substituents selected from the OH 0 group consisting of lower alkyl, halo, nitro and lower alk- 3 oxy; and X is an anion of an acid of pKa not above 4; which comprises reacting a benzodithiolethione of the /CH 1 01 or formu a.

OH; R

s -s This product is prepared by the procedure of Example R1 l 1, using 6-methoxy-benzo-1, 2-dithiole-3-thione in place of the thione used therein.

Example 7 I I s-s A solution of 1.84 parts of 4,5-benzo-1,2-dithiole-3- thione and 1.15 parts of thiophosgene in 50' parts by volume of chloroform is stirred overnight. After the 0 wherem R and R1 are as above'defined, Wlth all ln addition of 1.26 parts of dimethylaniline, the mixture is 0f the fmmula again stirred overnight. Digestion with dilute HCl fol- R1 lowed by perchloric acid gives the blue dyestuil of EX- ample 1. R

Example 8 3 wherein R and R are as defined above, in the presence of a catalyst selected from the group consisting of trichloromethanesulfenyl chloride and thiophosgene; and 0 separating the product thus formed.

No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,141,891 July 21, 1964 Erwin Klingsberg It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, lines 37 to 51, for that portion of the formula reading:

' CI CSCI c1 csc1 or a read or C1 C S I C1 C=S same column 1, lines 37 to 51, for the lower right-hand portion of the formula reading:

line 71, for "N,Ndimethyl" read N,Ndimethylcolumn 2, line 1, for "'L-Nmethyl" read -Nmethyl line 32, for "degree are in centigrade" read degrees are in Centigrade Signed and sealed this 24th day of November 1964.-

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J, BRENNER Attesting Officer Commissioner of Patents 

1. A COMPUND OF THE FORMULA: 